Substance abuse and psychiatric involving psychotic frequently co-occur in clinical populations. These dual diagnosis are associated with poorer patient functioning, treatment participation, and clinical outcome. A major impediment to patients' successful management of their dual disorders has been their deficits in intrinsic motivation to change their behavior in areas highly pertinent to their successful recovery (e.g., alcohol and drug abstinence, medication and treatment compliance). Motivational interviewing represents a very promising strategy for enhancing dual diagnosis patients' motivation for changes. It is clinically relevant in an era a brief treatment and managed are review, readily adaptable to psychiatric conditions, already manualized for substance abusers, and efficacious as a brief intervention with adult alcoholics. We propose to develop a two-session motivational pre-admission interview for substance abusing patients with psychotic disorders (Schizophrenia Disorder, Schizoaffective Disorder) as a means to enhance their motivation for change, increase their program participation, and improve their treatment outcome. The specific goals of this Stage I behavioral therapy development study are to: 1) pre-pilot (n=15) and develop manuals for dual diagnosis focused motivational enhancement therapy interviewing (DD-MET) and a standard pre-admission interview for a usual care control condition; 2) develop a DD-MET training manual, train therapists, and develop adherence and competence rating scales; (3) conduct a pilot study of the DD-MET manual, which will evaluate the efficacy, feasibility, and acceptability of DD-MET in comparison with a standard pre-admission interview; 40 substance abusers with psychotic disorders seeking treatment in a dual diagnosis partial hospital/intensive outpatient program will participate. Primary outcomes of the pilot study will be: a) percent days abstinent from drugs and alcohol and time to first drug or alcohol use, b) percent days compliant with medications and time to first medicational non-compliance, c) days in treatment (attendance and length of stay), d) patient ratings of motivation to change, and e) patient satisfaction with the interview sessions.